1. Field of the invention
This invention relates to a method and apparatus for producing both noncoherent and coherent intense monochromatic light from a continuous low temperature plasma. More particularly, this invention relates to a method and apparatus for the production of radiation in the form of intense monochromatic light from a continuous low temperature plasma generated in a region having a high density of atoms in metastable atomic states and in which the neutralization of ions by recombination with electrons proceeds at a very rapid rate. By selecting the gas it is possible to produce light at many different wavelengths. The use of helium to give 584-A ionizing light is an example of an interesting case. The method and apparatus are applicable both to noncoherent light sources and to coherent light sources of the commonly called lasers.
2. Description of the Prior Art
As has been set forth by two of the inventors in an article entitled, "Intense 584-A Light From a Simple Continuous Helium Plasma," which was originally published in Volume 135, No. 5-A of "The Physical Review" at pages A-1247 through A-1252 on Aug. 31, 1964, the importance of ionizing radiation in inducing chemical reactions is widely recognized. An intense monochromatic source of light in the far ultraviolet region is highly desirable in space research to study the chemical effects of solar ionizing ultraviolet radiation. Such a source, of course, also has many other scientific and industrial applications which are well known to those skilled in the art. It should be noted, for example, that the particular source described herein is also suitable for use as a vacuum ultraviolet laser when hydrogen or helium three is used in combination with helium four as will become apparent from the discussion below. Of course, the more common laser wavelengths may also be induced by an appropriate selection of gases and conditions, i.e., temperature, pressure, current, voltage, and magnetic field intensity.